A signal may be encoded with information and then amplified to broadcast or transmit the signal. High efficiency amplification can be performed with some systems achieving almost 60% energy efficiency. However, energy may be wasted if the system is designed for linear amplification. If linear amplification is performed, energy efficiency may drop down to as low as 10%. Linearization may be desired in order to make sure that the signal prior to amplification corresponds linearly to the signal post amplification.
In some systems, the signal itself may include content defined by amplitude modulation. For example, radar systems may have a fixed amplitude that is sent out. Other systems may use amplitude modulations to embed information into outgoing signals. Amplitude modulation may require linearity because each peak in the signal may transmit some valuable information. Thus, between the minimum and maximum values of the signal, the output of the power amplifier may need to correspond linearly to the input of the power amplifier in order to maintain integrity of the information being transmitted.
Various techniques may be used to create linear signals for communication systems or other systems or purposes. As discussed above, some systems may require substantial linearization, which may be performed at a single power amplifier. Each power amplifier may have an apparatus or multiple components surrounding the power amplifier which may allow the power amplifier to create highly linear signals. For example, a base station or phased array may use a power amplifier with a linearization circuit, but as discussed above, this may sacrifice energy efficiency. Thus, it may be desirable to have efficient high-power linear amplifiers for base stations or other communication systems. It may also be desirable to have groups of efficient high-power linear amplifiers, which may be used in, for example, phased array antenna systems.